Full Dose Cyclophosphamide with the Addition of Fludarabine for Matched Sibling Transplants in Severe Aplastic Anemia

The recommended therapy for severe aplastic anemia (SAA) in younger patients with a matched sibling donor (MSD) is allogeneic hematopoietic cell transplantation (allo-HCT). A number of conditioning regimens and protocols have been used for these patients. Here we report a homogeneous cohort of SAA patients receiving a uniform transplantation protocol. This study is a retrospective analysis of 82 consecutive patients with SAA who underwent MSD allo-HCT at a single center. The median duration of follow-up for survivors was 100 months, the 10-year overall survival (OS) was 87.5%, and the 10-year event-free survival was 75.3%. The OS was 97.4% for “mobilized” bone marrow (BM) graft recipients and 78.9% for “nonmobilized” BM graft recipients (P =.01. The cumulative incidence of acute graft-versus-host disease (GVHD) was 25.6%, that of chronic GVHD was 27.16%, and that of graft failure was 16.2%. Recipient age ≥30 years and transplantation at >6 months after SAA diagnosis were associated with a increased risk of events. In the presence of a fully matched sibling donor, allo-HCT with a mobilized BM graft and fludarabine-cyclophosphamide conditioning is an efficacious and safe approach. Early transplantation is associated with a better outcome, emphasizing the importance of not delaying transplantation in these patients. Prospective trials are needed to determine the optimal regimen.